I’m getting an error; could you tell me how to fix it?

19:22 [Error] Failed to call hook 'Unload' on plugin 'Convoy v3.0.6' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.Convoy+EventLauncher.StopEvent (System.Boolean isPluginUnloadingOrFailed) [0x00000] in <c84acdf9fdab42d6a6349f4f43a3ae6f>:0 
  at Oxide.Plugins.Convoy.Unload () [0x00000] in <c84acdf9fdab42d6a6349f4f43a3ae6f>:0 
  at Oxide.Plugins.Convoy.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x01ddb] in <c84acdf9fdab42d6a6349f4f43a3ae6f>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <42f9bedc659b4f4786eb778d3cd58968>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <15f61ddda771464d8246ebdce8ff4811>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <15f61ddda771464d8246ebdce8ff4811>:0 
19:22 [Info] Unloaded plugin Convoy v3.0.6 by Adem

Hey! Could you tell me a bit more about when this error occurs? Does the event start on your server? Does this error happen every time the event ends?

Changed Status from Pending to Work in Progress